Milliarcsecond Change of IM Pegasi Radio Position in 1 Hour Coincident with Sharp Rise in Flux Density

Autor: D. E. Lebach, Irwin I. Shapiro, Jean-Francois Lestrade, R. R. Ransom, M. I. Ratner, Norbert Bartel, M. F. Bietenholz
Rok vydání: 1999
Předmět:
Zdroj: The Astrophysical Journal. 517:L43-L46
ISSN: 0004-637X
DOI: 10.1086/312026
Popis: Continuum VLBI observations at 3.6 cm of the RS CVn binary star IM Pegasi (HR 8703) for ~16 hr beginning on 1997 January 16 revealed an apparent motion of the star's radio position that coincided temporally with a large relative change in its flux density. Specifically, a rise in flux density from 18 to 46 mJy in 1.4 hr coincided with a detected position change over that interval of (Δα, Δδ)=(-0.68±0.15, 0.55±0.20) mas. The magnitude of this position change is much larger than can be explained by parallax, proper motion, and orbital motion and is about two-thirds the estimated angular diameter of the primary component of the binary.
Databáze: OpenAIRE